1. Field of the Invention
The present invention relates to conveyor systems, and more particularly to a conveyor system using a continuous conveyor belt particularly adapted for the food service industry for transporting food trays and the like, including an ultraviolet irradiation system for disinfecting the conveyor belts at a position remote from the portion of the conveyor used to convey food products.
2. Background of the Invention
In hospitals and other institutions which have a centralized food preparation location, meals are often prepared along a conveyor belt carrying food trays across a series of stations at which appropriate meal portions, dishes or beverages are placed on the conveyor. Such conveyors typically have a straight flight path with an endless belt supported on pulleys defining the path. The belt typically will run in an upper flight path on which the trays are carried, and a lower flight path below a conveyor bed. The lower flight path is either exposed to whatever is below that flight path, or is contained within a support plate to try to prevent contamination of food products or the like that may be moved below the conveyor.
Because of the continuous operation of these belts in a large room where various food products are handled, it is possible for the conveyor belts to become contaminated with food products, bacteria or the like. Typically, in the past, such conveyors were periodically taken out of operation and sanitized using soaps and decontaminating chemicals. This is a time consuming and expensive process. To overcome that, it has been proposed in the past to devote a section of the conveyor's surface path of travel to passage through a hooded housing containing a plurality of UVC lights to expose the belt to irradiation from the lights for disinfection. Such previously proposed UV disinfection systems take up a substantial amount of space on the useful conveyor surface, and may require food products on the conveyor belt to pass through the UV light housing itself.
In addition, access to the belt in these housings is difficult and the housing size will vary depending on belt speeds. Thus, for example, the faster the belt speed the longer the housing must be in order to properly decontaminate the belt.
Some of the problems associated with prior art conveyor belts for the food service industry have been overcome by the conveyor system disclosed in U.S. Pat. No. 5,052,548, the disclosure of which is incorporated herein by reference.
As disclosed in that patent, the conveyor system is used for transporting food trays, soiled trays and the like. The system includes a frame which defines a conveyor path of travel of relatively great length, and typically having one or more horizontal curves or turns therein. A pair of corresponding conveyor beds are mounted on the frame and define upper flight paths to move the food trays or soiled trays thereon. In food preparation, a plurality of work stations are positioned along one side edge of each of the conveyor beds. A different item, such as food or beverage or their associative condiments are placed on the trays at each of the work stations. In soiled tray systems, soiled dishes are transported from the cafeteria to the ware-washing area.
The conveyor belt disclosed in U.S. Pat. No. 5,052,548 includes a pair of endless belts mounted in the frame for movement along a conveyor path of travel between corresponding upper and lower return flight paths. The drive mechanism of this system allows the return belt path to be positioned above the conveyor bed. The belts are constrained within a box channel on their lower return flight paths remote from the work stations, thereby to maintain a sanitary environment for food tray preparation or soiled trays.
Despite the advantages of that system, it is still possible for the conveyor belts to be contaminated with excess food products or bacteria, viruses or the like. While a conventional UV hood arrangement over the conveyor path of these belts would serve to partially decontaminate the belts, it would not be possible to decontaminate all sides of the belts using that system because both sides of the belts are not exposed in the conveyor flight path. Moreover, as with conventional systems, the UV hood arrangement would take up excess space in the useful conveyor flight path. Therefore, conventional UV systems would not be satisfactory for use with this type of conveyor system.